Vidu Q2 vs Q3 Pro Guide: When Newer Means Fewer Modes

The assumption is usually safe: a newer model generation adds capability on top of the last one. Vidu breaks that assumption. Q2 ships as four endpoints covering text-to-video, image-to-video, start-end-to-video, and a fast image-to-video variant. Q3 Pro ships as two: vidu-q3-pro-t2v and vidu-q3-pro-i2v. Two whole modes disappear between generations, and picking Q3 Pro by default because it's newer is the wrong move for a chunk of real use cases.

Key Takeaways

• Q3 Pro has only t2v and i2v. Q2 also has vidu-q2-pro-se2v (start-end-to-video) and vidu-q2-pro-fast-i2v, and neither carries over to Q3 Pro.
• Q3 Pro adds two things over Q2, both generation-wide rather than i2v-specific: an optional seed field (up to 9999999999) on both t2v and i2v, and a 540p size tier below Q2's 720p/1080p floor on both endpoints.
• Neither generation has a reference-video (ref2v) mode. That gap predates Q3 Pro; it isn't something the newer generation lost.
• Pricing for both generations is unverified on Siray right now — this guide compares capability only, not cost.

What Q2 Has That Q3 Pro Doesn't

vidu-q2-pro-se2v takes exactly two images — the images array is fixed at minItems: 2, maxItems: 2, a start frame and an end frame, not "up to two." It runs at 720p or 1080p, supports duration of 4 or 8 seconds, and has audio_enable. There's no equivalent se2v endpoint anywhere in the Q3 Pro lineup. vidu-q2-pro-fast-i2v is the other casualty: a faster image-to-video variant that exists only on Q2. If your workflow depends on start-end framing or the fast tier specifically, Q3 Pro isn't an upgrade for you — it's an endpoint that doesn't exist yet on the new generation. This kind of non-monotonic change isn't unique to Vidu — Pixverse shows the same pattern with its duration field: the newer-numbered pixverse-v5.6-i2v tightens the allowed range to three fixed values ([5, 8, 10]) while the older pixverse-c1-i2v still accepts any integer from 1 to 15 seconds (see the Pixverse V6 menu video guide for the full field comparison). A higher version number doesn't guarantee a superset of capability in either family.

The Two Things Q3 Pro Actually Adds

vidu-q3-pro-i2v and vidu-q3-pro-t2v both support an optional seed field with a maximum value of 9999999999. Neither of Q2's corresponding endpoints, vidu-q2-pro-i2v and vidu-q2-t2v, has a seed parameter at all. That's a real, useful addition for anyone who needs to reproduce a specific output or iterate on one seed while changing the prompt — and it's a generation-wide change, not something specific to image-to-video.

Q3 Pro also opens up a 540p size option on both endpoints. Q2's t2v and i2v both cap their size enum at two values, 720p and 1080p; Q3 Pro's versions add 540p below that shared floor. For anyone iterating on cheap, fast drafts before committing to a full-quality render, that's a second small win layered on top of seed — lower resolution means faster, cheaper generations while a prompt or seed is still being dialed in.

Outside of those two additions, the endpoints otherwise match closely. Both i2v pairs share the same aspect_ratio enum (16:9, 9:16, 1:1, 4:3, 3:4) and the same duration options (4 or 8 seconds), with audio_enable on both generations.

Picking a Generation by Task

Need start-end-to-video for a fixed first and last frame? Stay on vidu-q2-pro-se2v — there's no other option in this family. Need image-to-video with a reproducible seed for A/B iteration on a prompt? vidu-q3-pro-i2v is the only endpoint in the family that offers it. Doing plain text-to-video with no reproducibility requirement? Either vidu-q2-t2v or vidu-q3-pro-t2v works; nothing in the spec differentiates them beyond generation number. For a first/last-frame workflow specifically, the renovation before-and-after guide covers what vidu-q2-pro-se2v's two-image constraint looks like in a concrete before/after use case. For a quick draft pass where speed matters more than final quality, running vidu-q3-pro-t2v or vidu-q3-pro-i2v at 540p is the cheapest way to preview a shot before committing to 720p or 1080p — an option neither vidu-q2-t2v nor vidu-q2-pro-i2v offers.

What This Guide Doesn't Cover

Two things on purpose. First, pricing: neither generation's cost is verified against Siray's console as of this writing, so this comparison stays capability-only — treat any per-second number you see elsewhere as unconfirmed until checked directly. Second, reference video: no Vidu endpoint in the current product lineup, Q2 or Q3 Pro, offers a ref2v mode. That absence isn't new to Q3 Pro — it's a gap across the whole family, not a regression.

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